Why are they so popular and do they really improve the handling of a car? In theory, when you lower your car, you also lower its center of gravity, therefore reducing body roll and improving handling. However, the car’s handling characteristics are not only determined by the center of gravity. You also need to take into account the damping system, damping rate, road conditions, tire sidewalls, unsprung weight, tire grip, suspension geometry, etc.
Right now we are only interested in the ever so popular coilover setup. There are many aftermarket manufacturers that feature different brands and types of shock absorbers. Coilovers are popular with racers due to their adjustability. You can adjust the correct height and in some cases you can also adjust the damping to produce excellent handling.
There are two types of coils. They are true coilovers and sleeve type coilovers. True coilovers are a setup where the shocks have one threaded body, while the other uses a ‘sleeve type’ thread. One of the oldest and best known manufacturers of coilovers is H&R. Now, there are different companies like Tein, Intrax, etc. They also make coils. However, Ground Control was the pioneer of sleeve designed coilovers. We have no doubts about the benefits of true coilovers. But what about the type of manga? Works? In theory, it works just like real coilovers. In real life, it doesn’t even come close to springless shock and spring setups.
Ground Control, the pioneer in hose design technology, uses aluminum body hoses with Eibach race springs. The base of the spring is supported by a single swivel plate with an Allen screw locking device. What’s wrong with this design you ask for? Like all ‘sleeve type’ coilovers, there is a good chance that the sleeve will turn and thus cause the spring to slip. This can happen to enthusiastic drivers who like to push the car to the limit. The other thing that concerns me is the Allen screw locking device. Such a small screw has the function of maintaining the tension and twist that the car generates when an enthusiast drives it.
Weapon-R Tuner 2 coilover conversion. This is basically the same with Ground Control, except added the extra locking plate (with the same Allen screw that locks it in place) supposedly for added security.
Skunkworks and Aerospeed. Both of these companies use true coilover type lockout devices. Double plates interlocked with each other. This is by far the best setup so far. But how about the sleeve? Something must be done to secure the sleeve.
These disadvantages can not only create metallic noises, but can also be very dangerous. Picture this: you’re cornering really fast, relying on that great suspension to do its job, when the lock/sleeve plates moved creating a sudden lurch in your suspension (like when driving across an uneven surface) and so Therefore, he lifted his tire off the ground thus losing traction……….
So why is it so popular? Because it’s cheap ($249-$399 US) compared to true coilovers ($1,200 US and up). It looks great, it’s adjustable and again makes your car look great…
beware of drivers
The proper way to adjust a threaded coil suspension involves the use of a set of scales. The general idea of this type of suspension adjustability is to match the loads on the tires (or bias them for the circular track) for cornering ability. The fact that you can lower the car with them is just an added benefit, but it is NOT their main function. You should be aware that you can hurt your car’s performance if you don’t adjust them at least reasonably close. At best, the car may not corner as well as it used to.
In the worst case, it can change the handling to the point of being dangerous. This sounds like overkill, but with a threaded setup you could load the front right and rear left tires and create a car that turns left just fine, but doesn’t turn right. Even possibly going around. All this with the car perfectly level. You’ve got the suspension, now take the time to set it up right. Find a tire shop with some corner scales and work with them to adjust the tire load and ride height. The goal is to equalize the cross weights (diagonal weights). It is not so important to match the other weights. It’s the crossed weights that will sneak up on you.